tools: ynl-gen: split presence metadata

Each YNL struct contains the data and a sub-struct indicating which
fields are valid. Something like:

  struct family_op_req {
      struct {
            u32 a:1;
            u32 b:1;
	    u32 bin_len;
      } _present;

      u32 a;
      u64 b;
      const unsigned char *bin;
  };

Note that the bin object 'bin' has a length stored, and that length
has a _len suffix added to the field name. This breaks if there
is a explicit field called bin_len, which is the case for some
TC actions. Move the length fields out of the _present struct,
create a new struct called _len:

  struct family_op_req {
      struct {
            u32 a:1;
            u32 b:1;
      } _present;
      struct {
	    u32 bin;
      } _len;

      u32 a;
      u64 b;
      const unsigned char *bin;
  };

This should prevent name collisions and help with the packing
of the struct.

Unfortunately this is a breaking change, but hopefully the migration
isn't too painful.

Link: https://patch.msgid.link/20250505165208.248049-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/net/ynl/samples/devlink.c b/tools/net/ynl/samples/devlink.c
index d2611d7ebab4..3d32a6335044 100644
--- a/tools/net/ynl/samples/devlink.c
+++ b/tools/net/ynl/samples/devlink.c
@@ -34,7 +34,7 @@ int main(int argc, char **argv)
 		if (!info_rsp)
 			goto err_free_devs;
 
-		if (info_rsp->_present.info_driver_name_len)
+		if (info_rsp->_len.info_driver_name)
 			printf("    driver: %s\n", info_rsp->info_driver_name);
 		if (info_rsp->n_info_version_running)
 			printf("    running fw:\n");